The authors interpret fluctuations in GNP and unemployment as due to two types of disturbances: disturbances that have a permanent effect on output and disturbances that do not. They interpret the first as supply disturbances, the second as demand disturbances. Demand disturbances have a...

Are business cycles mainly the result of permanent shocks to productivity? This paper uses a long-run restriction implied by a large class of real-business-cycle models--identifying permanent productivity shocks as shocks to the common stochastic trend in output, consumption, and investment--to...

Mixing across racial and ethnic lines could spur understanding or inflame tensions between groups. We find that white students at a large state university randomly assigned African American roommates in their first year were more likely to endorse affirmative action and view a diverse student...

Many open-access resources, such as elephants, are used to produce storable goods. Anticipated future scarcity of these resources will increase current prices and poaching. This implies that, for given initial conditions, there may be rational expectations equilibria leading to both extinction...